Anti-erythrocyte antibodies (TER119 and M1/69) do not require the inhibitory Fc receptor FcγRIIB in the amelioration of murine ITP. (A) FcγRIIB^+/+ (C57BL/6) and (B) FcγRIIB^–/– mice were injected with 2 μg antiplatelet antibody on days 0 to 3 (↑). All mice received an injection of 200 μL PBS (▴) or 2 g/kg IVIg (○) or 50 μg TER119 (▵) or M1/69 (□) on day 2 (↓). The x-axis denotes the days, the y-axis denotes the platelet count; n = 7 for each group. Data are expressed as mean ± SEM.